A wireless telemetry system for a turbine combustion is disclosed in U.S. application Ser. No. 11/936,936, which is incorporated herein by reference. As disclosed therein, a high temperature wireless telemetry system may be powered by induced RF energy generated by air gap transformers including a transformer primary induction coil assembly that is stationary and a secondary induction coil assembly that rotates. The telemetry system includes at least one sensor deposited on a component such as a turbine blade. A telemetry transmitter circuit is affixed to the turbine blade and a connecting material is deposited on the turbine blade for routing electronic data signals from the sensor to the telemetry transmitter circuit, the electronic data signals indicative of a condition of the turbine blade. An induction power system is provided for powering the telemetry transmitter circuit with a rotating data antenna affixed to the root of the turbine blade, such as the turbine blade; and a stationary data antenna affixed to a static seal segment adjacent to the turbine blade.
As shown in FIG. 1, the prior art telemetry transmitter assembly 300 is mounted to a side of a platform 301 supporting a turbine blade 302. The transmitter assembly 300 is in electrical communication with a sensor (not shown) on the blade 302 via a first electrical connection 304. The transmitter assembly 300 includes a cover member 303 bolted to a bracket member 305 with a transmitter circuit board disposed therebetween. The assembly 300 may be affixed to a transition area of the platform 301 in a recess 306 using an epoxy, adhesive, brazing, transient liquid phase bonding, diffusion bonding, welding, mechanical fixation, such as bolting, or any other joining method known to those in the art. A backfill material may be placed over them for protection from high temperatures or particulate debris.
A rotating data antenna assembly 308 is mounted to a face of the turbine root 301, and is in electrical communication with the transmitter assembly 300 via a second electrical 310. The antenna assembly 308 includes an induction coil and antenna secured within an RF transparent ceramic cover 311, which is mounted to the face of the blade root 309 using a bracket 313. The cover 311 includes flanges 312 secured in the bracket 313, and the flanges 312 are oriented on the root 309 parallel with, rather than perpendicular to, the centrifugal force direction (represented by the arrow labeled “C”) of the rotating blade 302, so the ceramic cover 311 is loaded in compression and not in bending.
While the above-described rotating antenna assembly 308 works for certain turbine engine designs, it may not be compatible with turbine blade sections that incorporate seal plates. Seal plates are often mounted to a turbine rotor disc on which the rotor blades are fixed to seal cooling fluid paths. However, the above-described rotating antenna assembly may not be used with seal plates. There is insufficient space between the seal plate and face of the root blade, and if the antenna assembly is capable of being mounted to the blade root face, the seal plate would interfere with transmission of signals from the antenna.